Being confronted by exactly that issue on my previous boat, my solution was to let the professionals inspect the shaft and advise you on whether or not to replace the assembly. You may be pleasantly surprised by the repair capabilities of a qualified hydraulics service facility. The major cost of your repair will be removal and replacement of the hydraulic ram, so doing that yourself saves $$. And, if you take the ram to a repair facility, and they can successfully save your rod, you've saved a bunch over the cost of replacement of the entire assembly.
Capilano and/or Seastar should be able to cough the name/number of a local repair facility. If not, try Redden Marine in Bellingham, WA. They did mine (twice), and are pretty good.
Attempting to disassemble the ram, R&R the rod, install new seals, and reassembly yourself is not usually successful, as the tolerances in a typical hydraulic ram are well beyond what the typical amateur boater can accommodate in his garage. So save the big bucks by unbolting the thing, hauling it to your local hydraulic shop (and it doesn't have to be a "marine" facility either. Hydraulics are hydraulics, whether in a low rider or aboard a boat), let them do their thing, and go from there.
Kind of a middle ground between trying to butch up a repair yourself, and simply throwing money at new parts. Kinda like boatwrights used to do in the old days.